Is the foundation of the model generation process. Examples of background knowledge sources in QMRA area are: published scientific studies, unpublished studies, national or international official data, surveys and questionnaires, risk assessments carried out by national or international agencies and research institutes, expert knowledge elicitation and expert opinion and events (e.g. meeting or conference). It can be classified, for instance, into data-driven knowledge (e.g. predictive microbiology data, food consumption data) and model-based knowledge (e.g. PM models, models from previous risk assessments).